ACTIVE COOLING

Even if you are using natural ways to keep comfortable when temperatures are high, you may still feel too warm and choose to use electrical appliances to cool the air in your home during summer. However changing the air temperature takes a lot of energy, so here are some tips to get a balance that works for you.

AIR CONDITIONING

Air conditioning can give greater control of comfort in any climate. An AC will typically consume 10 times more energy than a fan.

For efficient air conditioning, the house or room should ideally be well sealed and well insulated. Windows should also be shaded from the summer sun.

Avoid leaving the air conditioner running when no one is home. It is cheaper to cool the house down when you arrive home.

BUYING THE RIGHT ONE

When buying an appliance always choose the most efficient model for your application. You can use the Australian Institute of Refrigeration, Air Conditioning and Heating online tool www.fairair.com.au to help you choose the right system for your specific room characteristics.

Once you know the size of system you need you can compare the star ratings to get the most efficient model you can afford. If you expect to use it often, then getting the highest star rating is important as running costs may quickly add up to be more than the purchase cost.

Fixed systems need to be installed by a licensed refrigeration mechanic/electrician.

REPLACING AN OLD UNIT

For existing or old air conditioner units consider how often you use it for cooling before buying a new one. If you rarely use your old unit then it doesn’t make sense to buy a new one. If it is old but you use it a lot, then you may be better off buying a modern and more efficient air conditioner. You could also buy a reverse cycle air conditioner, as these are actually a very efficient way to heat the home in winter, though you should still try to manage how often you use it to keep costs down.

WHAT'S THE RIGHT TEMPERATURE

Hot weather can make you want to set the cooling all the way down to 21°C. But cooling to just 26°C should keep your home comfortable and save you money. Setting your thermostat just 1°C cooler can increase your cooling bill by 15%. Remember bodies do acclimatise to the heat so the main thing is to just take the edge off and get the temperature to something comfortable, rather than over cooling the room or home.

Setting the thermostat at a temperature lower than you need will not make the unit cool faster, so this is unnecessary.

FANS

Fans should be the first choice for mechanical cooling. They are the cheapest cooling option to run and have the lowest greenhouse impact. Typically, the air flow created by a fan provides a similar improvement to comfort as reducing the air temperature by around 3°C.

Fans can be either portable (pedestal fans) or fixed (ceiling/wall fans). Fixed fans are often better in areas like the bedroom where they are out of the way and always required in the same location. Portable fans are more suited to areas like the living room where you can position the fan wherever it is needed throughout the day.

If you use a fan, direct the flow of air to your face. It’s more effective because the face has so many receptors on it.

If the outside temperature is lower than the temperature in your home then the fan will be much more effective if it is placed next to an open window, as this will draw air from outdoors, which should be cooler.

Portable fans vary considerably in how much they move and how much noise they make. Choose one that suits your situation – for example, a quiet fan is usually the best option for a bedroom.

COMBINING AIR CON/FAN

Using fans in combination with an air conditioner means you can set the air conditioner to a higher temperature in summer (add at least 3°C) and still feel the same. The combined energy cost will be far less than running an air conditioner alone.